The proposed work consists of the following four projects: 1. Quantitative Characterization of the In Vitro Neoplastic Transformation of Syrian Hamster Embryo Cells (SHE cells, 13-days gestation) - The Development of Carcinogenic Bioassay. 2. Somatic Genetics on the Progression in Neoplastic Transformation: Studies of the Spontaneous Initiation and Progression Toward Neoplastic Transformation of Syrian Hamster Cells. 3. Changes in Gene Expression Accompanying Neoplastic Transformation. 4. Transformation of Syrian Hamster Embryo Cells by HSV-2 DNA. Considerable progress has been made as in the sections reported below: 1. Perturbation of Mammalian Cells by Macromolecules (Nucleic Acids and Enzymes) via Liposomes as Carriers - Neoplastic Transformation by DNase I Entrapped in Liposomes. 2. Detection and Characterization of Subpopulations of Contact-Insensitive and Anchorage-Independent Cells in Syrian Hamster Embryo Cell Cultures. 3. Senescence and Neoplastic Transformation of Syrian Hamster Adult Fibroblast. 4. Effects of Ploidy (Gene Dosage) on Somatic Mutation, In Vitro Senescence, and Neoplastic Transformation. 5. Analysis of Specific Cell Surface Antigens (Proteins) from Tumorigenic Cells. 6. Induction of Heteroploidy in Diploid Human Fibroblasts Antimitotic Agents. 7. Role of HSV-2 Gene Expression in Transformation. 8. Identification of HSV-2 mRNA in transformed Cells by In Situ Hybridization. 9. Identification and Localization of the Oncogenic Fragment of HSV-2 DNA. 10. Neoplastic Transforming Activity of Bg1 II N Fragment. 11. Phenotypic and Antigenic Properties of Cells Transformed by Restriction Enzyme Fragments of HSV-2 DNA.